Intelligence agencies practice what is known as 'false flagging', recruiting sources by posing as spies from one country when in reality they are working for another. The KGB was notorious during the Cold War for impersonating Israeli spy agency Mossad and recruiting Jewish citizens of Western countries who thought they were providing information to help Israel when in fact they were unwittingly aiding their enemies. Philip's girlfriend thinks she is helping neutral Sweden and therefore what she is doing is relatively harmless when in fact she is unknowingly working for the Soviets.

During the Cold War the KGB and GRU concealed supplies of weapons and equipment in Western countries so that if real war broke out their agents would become full blown saboteurs, carrying out attacks against strategic targets and assasinating key personnel. Several such caches were uncovered by the authorities, one in Switzerland boobytrapped and exploding when it was opened and one in Sweden found to contain files including the pictures, names and addresses of many of the country's fighter pilots. According to some sources KGB caches concealed in the Shenandoah Valley area contained toxins intended for poisoning Washington's water supply and even mini-nuclear weapons.

The Russian characters on the show(mainly the characters in the Rezidentura) are actually not referring to each other by first and last name, rather, they are referring to each other by a first name and patronymic. Russian names are comprise of 3 parts, a first name, a patronymic(which is derived from the father's first name), and a last name/surname.

For an example, there is a Russian guy named Pavel and his father's name is Ivan, therefore his first name and patronymic would be Pavel Ivanovich. His full name could look like Pavel Ivanovich Mishkin. Or quite literally, Pavel son of Ivan Mishkin.

For women, the same rules apply, but the ending is feminine for the patronymic. If there is a woman named Anastasia, and her father's name is Sergei, then her name and patronymic would be Anastasia Sergeevna.Anastasia daughter of Sergei.
Her full name could be Anastasia Sergeevna Mishkina. Notice the feminine ending with "a".

-ovich and -evich are attached to the ending of first names for males to form a male patronymic, whereas -ovna and -evna are attached to the ending of first names for a female's patronymic.

In some ways very much so, the KGB and its' post-Soviet successors really did have deep cover agents within American society posing as ordinary famillies, specializing in recruiting intelligence sources and gathering information on technology. Amongst the items stolen were the designs for silent submarine propellers and stealth technology. In response the US really did leak them false information, notably computer programmes with built in flaws which had a disasterous effect on Soviet industry when they attempted to use them. However there is no evidence that the KGB ever killed anyone on US soil during the course of the Cold War.

Dead drop; a pre-arranged location where spies can drop off and pick up information, supplies etc without ever having to meet one another face to face.

GRU; Glavnoye razvedyvatel'noye upravleniye -translation-Main Intelligence Directorate of the General Staff. Soviet Military Intelligence organisation and frequent rival of the KGB.

Illegal; spies who are not covered by diplomatic immunity. Most agents operate out of their country's embassy and covered by a legal diplomatic protection. This means that if they are caught the worst that could happen is that they are expelled from their host country. The central characters in The Americans are illegals with no such protection who could face prison or even execution if apprehended.

KGB; Komitet gosudarstvennoy bezopasnosti-translation-Committee for State Security. The Soviet Union's espionage body dedicated to security and political intelligence both at home and abroad.

Sleeper; agent placed under long term cover and left dormant awaiting activation.